Survey specialist Fugro Aperio has carried out a ground penetrating radar (GPR) investigation at London's Heathrow Airport to locate underground utilities in preparation for the development of new taxiways.
Construction, infrastructure and design company, Morgan Sindall, commissioned the GPR survey on behalf of the client, Heathrow, to support completion of the design for the new taxiways.
Cambridge-based Fugro Aperio used Kawasaki Mule 4×4 utility vehicles to fast track the scanning of over 100,000 sq m of ground in one of the largest utilities location projects so far tackled by its transport team.
Charlie Baker, Fugro Aperio project manager, said: "We deployed extra geophysicists to ensure we could successfully survey nine separate areas within limited night shifts and a four-week schedule. Mounting the radar kit on an all-terrain vehicle provided fast, flexible coverage of the open, turfed target sites."
Surveying was carried out adjacent to runways during 13 night shifts from 11pm to 5.30am. Mike Neumann, Airports Planning Manager at Morgan Sindall, said: "The GPR investigations were completed within the allocated timescale with no major issues."
The GPR survey was commissioned to supplement and corroborate data from C.A.T. and Genny surveys (cable and pipe detection) plus trial holes undertaken by Morgan Sindall in building a picture of subsurface utilities. GPR is a fast, cost-effective and non-destructive technique for imaging the shallow subsurface of engineered structures, pavements and made ground.
Morgan Sindall provided Fugro Aperio with initial drawings identifying telecommunications, electricity cables, drainage, fuel lines and fire mains based on Heathrow archive data, statutory records and cable location results from the C.A.T. and Genny survey. Fugro Aperio produced interim reports of GPR data throughout the delivery process to help Morgan Sindall target further trial pits and trenches.
"Positionally, the GPR results were very good," said Mr Neumann. "They helped to map buried services as well as confirming data from our other surveys."
He added: "In combination, the three survey techniques have provided an indication of the line and location of services running through the areas of interest. They have also given a degree of information on depth, although this will need further evaluation and further trial pits when the contract is awarded."
Fugro Aperio has undertaken other GPR surveys on runways and airside pavements at Heathrow, including a contract to investigate delethalisation slabs around access pits and chambers.